Biomaterial Database

Disinfection of sewage by ultraviolet irradiation. 1979

J A Myhrstad

Disinfection of sewage from an activated sludge process, and of sewage from an activated sludge process followed by chemical precipitation, has given very high killing rates for the indicator organisms examined. For coliforms, Escherichia coli and faecal streptococci, a killing rate of more than 999.99% was usually obtained, and the residual number of microorganisms in the irradiated sewage was very low. The killing rate increased with the irradiation dosage, depending on the intensity of the irradiation, ie the water quality, and on the irradiation period, ie the water flow. The study demonstrates that ultraviolet irradiation may be an alternative method to chlorination of sewage.

UI	MeSH Term	Description	Entries
D004203	Disinfection	Rendering pathogens harmless through the use of heat, antiseptics, antibacterial agents, etc.
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D012722	Sewage	Refuse liquid or waste matter carried off by sewers.	Sludge,Sludge Flocs
D013242	Sterilization	The destroying of all forms of life, especially microorganisms, by heat, chemical, or other means.
D013293	Enterococcus faecalis	A species of gram-positive, coccoid bacteria commonly isolated from clinical specimens and the human intestinal tract. Most strains are nonhemolytic.	Streptococcus Group D,Streptococcus faecalis
D014466	Ultraviolet Rays	That portion of the electromagnetic spectrum immediately below the visible range and extending into the x-ray frequencies. The longer wavelengths (near-UV or biotic or vital rays) are necessary for the endogenous synthesis of vitamin D and are also called antirachitic rays; the shorter, ionizing wavelengths (far-UV or abiotic or extravital rays) are viricidal, bactericidal, mutagenic, and carcinogenic and are used as disinfectants.	Actinic Rays,Black Light, Ultraviolet,UV Light,UV Radiation,Ultra-Violet Rays,Ultraviolet Light,Ultraviolet Radiation,Actinic Ray,Light, UV,Light, Ultraviolet,Radiation, UV,Radiation, Ultraviolet,Ray, Actinic,Ray, Ultra-Violet,Ray, Ultraviolet,Ultra Violet Rays,Ultra-Violet Ray,Ultraviolet Black Light,Ultraviolet Black Lights,Ultraviolet Radiations,Ultraviolet Ray
D014871	Water Microbiology	The presence of bacteria, viruses, and fungi in water. This term is not restricted to pathogenic organisms.	Microbiology, Water